Apparatus for making prints



1939. E. JOLLASSE 2,168,481

APPARATUS FOR MAKING PRINTS Filed Feb. 24, 1938 Patented Au 8, 1939 2,168,481

UNITED STATES PATENT OFFICE APPARATUS FOR MAKING PRINTS Erik J olla sse, Hanau-on-the-Main, Germany, as-

signor to Quarzlampen-Gesellschaft m. b. 11., Hanau-on-the-Main, Germany Application February 24, 1938, Serial No. 192,387 In Germany February 27, 1937 15 Claims. (Cl. 9541.5)

This invention relates to apparatus for making can be made of any other desired source of rays. prints, such as, blue prints, tracings, heliographs The accessory parts, for example the rheostat 4, or the like. The principal novelty of the present ignition or sparking means 5, switch and the like, apparatus over previously known apparatus of necessary for operating the discharge tube, are

this kind resides in the provision of a supporting placed in a chamber 6, one limiting wallof which 5 surface for the light-sensitive paper and for the is appr x m e y equ n height to t ss S eoriginal subject to be reproduced in the form of a tion of the half Cy der along the a The half cylinder which is of. material permeable to chamber 5 and the half cylinder Lare formed as a light rays and the interior of which contains, unit, this unity being Particularly emphasized y preferably axially directed, an elongated light the lateral walls 1, closing off both eha be 6 10 source, and wherein also the accessory instrud y de l at their ends Simultaneouslyents or' apparatus required for supplying the The size of the apparatus is determined by that source of light are located in a lateral part of Of e Or l o be p 50 that the length the housing which is closed off from th semiof the cylinder is equal to the greatest admissible cylinder. It is particularly important that the n r w e f h or whi e th n ude 15 axis of the half cylinder be horizontal and t of the longitudinal side of the original determines two longitudinal edges b arranged approximately the diameter of the half cylinder, or vice versa. vertically one above the other. The advantage of A the entire cylinder surface must. be irradiated this arrangement is that not only is the sensitive it is necessary to make the ray source 2 as s 0 paper easil applied th emi-cylinder but as possible. It is generally sufiicient if the illumialso that the hot air is easily carried from the hating Portion of the source, that is, the lighting interior thereof in that, for example, ventilating tube, is about the e length as e Se y openings are provided. b v 'b l parallel der. By means of the lateral extensions provided with the longitudinal edge of the semi-cylinder, by the retaining devices andcover sleeves pro- In any other arrangement of the half cylinder, vided at h n f he t he r y source will 25 35 sembled apparatus; while for example, in a vertical position .of th i have a length'greater than the spacing of the good ventilation can b btai d t not easy end walls. The end walls are therefore provided application of th paper with openings serving on the one hand to allow Many other objects and advantages of the insertion of the tube and from which, on the other vention will become apparent from the following hand, the ends of said tube project. The epeh- 30 detailed description and drawing. ings are closed by the caps 8 so that nothing can In the accompanyin dr i come in contact with the ray source and the leads Fig. 1 is a perspective View; I for the electric current. Fig. 2 is a longitudinal section through m g In view of the considerable load on the tube Figs. 3 and 4 are sectional views of constructive aeration must be Provided the interior of the details on section lines III-III and IV-IV; and h lf cylinder. Inthe arr n ment ac r n to Fig. 5 shows the circuit and connections of the the invention t s s as ly p s y the ray source for different intensities of light. aerating s ts d 10 p d above a d below and quantity of heat produced thereby, good 40 In Figs. 1 and 2, numeral l designates a half P e ith the longitudinal edg s Of the Semi- 40,

cylinder of material permeable to light rays, for ey1ihdei- In View Of t t thht. according to example of glass or other transparent material. the n n, e tW longitudinal es of the Inasmuch as ordinary print paper has a lighta y er are pp o y Vertically super; sensitive maximum in the long wave ultraviolet P d a go chimney action 0 draft is P i or in the violet or blue spectral range, it is suf- As one of the ventilating Op s s placed at 45 ficient if the cylinder is made of a material perthe highest P t, the hot Cannot-accumulatemeable for these wave lengths. The elongated W thout this. provision there is danger of the my source 2 is located at the interior of the semiglass cyl nd rae cylinder, preferably at its axis. The original to S previously stated, the Sensitive p p d be copied together with the sensitive paper is the orig are pplied aga st the half cylinder 50 placed outside on the cylinder surface and applied by means of the pressing cloth 3 which is, atfirmly thereagainst by a pressing cloth 3. The tached at its lower end to a transverse rod. The ray source 2 is for the most part a high actinic latter is spread out at its free end by means of radiator, particularly a high pressure mercury a rod ll extending therethrough. Its freev end is lamp with fixed, activated electrodes, although use provided with spaccd hooks I2 which engage in 55 openings, depressions, eyelets, or the like of the housing and the cloth 3 is pressed firmly against.

latter, when not placed on the cylinder, can be I spread out over the surface of plate l5. In this condition thesensitized paper and the original are placed on the cloth 3, then raised and applied on the cylinder; Plate I5 can be folded up when the apparatus is not in use.

Since it has been found that too much light passes through a white cloth, whereby the operators are dazzled, the cloth may be blackened on'the'back or made of opaque material. In order, however, thatthe change in color of the sensitized paper shall be recognized and the light out ofi, a small portion of the cloth is left transparent, for example by not blackening a narrow strip' it or, if the cloth itself is opaque, by providing openings therein. It is, however, possible, instead of these measures, to place an additionalscreen of opaque material outside of the cloth, this being provided withthe necessary observation openings.

' Inasmuch as a high pressure mercury lamp cannot be lighted anew-for eachindividual exposure, a rotary screen I1 is provided which, bymeans of an outwardly accessible handle it,

. can be oscillated about the axis of the ray source or ofthe half cylinder and serves for screening the copyin'g'surface. This dark position is shown on Fig. 2 by dotted lines, while the full lines show the other position in which the screen acts as a reflector which is so constructed-that it uniformly distributes the radiation reflected by it on the copying surface.

' When powerful light sources are used for making prints, 1 with a high pressure mercury lamp with a charge of 400-500 watts, the irradiating periods are 20-30 seconds, for example, the papers used for the production of reflex copies being considerably more sensitive, so that short irradiating periods are obtained with the same light source. For this reason a switch arrangement is built in the apparatus by means of which the charge ofsthe light source can be reduced. can be done, for example, by interposing an additional resistance of several 100 ohms in the circuit of the discharge tube, so that the mercury tube burns as a low pressure are and with a current intensity of less than l ampere. According-to the invention the additionalresist- --ance is to be calculated so that the intensity is reduced to less than ,one tenth. Instead of the In addition, a re-. flector is provided approximately perpendicularlyresistance the connection can also take place otherwise, for example by reducing the net potential by means of a transformer. The shifting to the difierent stages of intensity can also be efiected by means of the switch l9 which may serve to connect in and disconnect the ray source.

The source. is cut out when the switch indicator is in the two positions marked 0 (Fig. 1), while position 1, with the additional auxiliary resistance connected in, gives the lowest intensity, and position 2 the highest. Fig. 5 shows diagrammatically the operationof switch l9. The line potential is connected at the terminals 2B and 2!. In the position 1 the contacts a and c of-switch It are connected together by the contact yoke or bridge 22; in position 2" the contacts b and d, while in the out position the contacts a and b or c and d are connected with each other, so that in'both these cases there-is no potential at the discharge tube. The main resistance is designated by 23 in Fig. 5, the auxiliary resistance of several 100 ohms by 25. Figs. 3 and 4 show the tensioning device for the cloth 3 in greater detail. Cloth 3 has a seam at the end which covers the rod It, which cloth is firmly attached to the rod by means of a;resilient sleeve 25 "slid thereover. The length of the cloth can be adjusted as desired by turning the rod l4 which is retained by screwing on a clamping member 26 which presses the rod firmly against the housing-of the apparatus.

I claim:

LApparatus for making prints on lightsensltivesheets comprising a housing having a semicylipdr.ical light transmissive surface disposed with a substantially horizontal axis and having one longitudinal edge superposed above the other, an elongated light source disposed substantially along the axis of the semi-cylindrical surface, said housing being provided with ventilating openings extending substantially along the longitudinal edges of the semi-cylindrical surface and substantially coextensive therewith.

2. Apparatus \according to claim 1 in which the superposed edge of the semi-cylindrical surface is substantially vertically above. the other .edge thereof.

Apparatus according to claim 1 in which the source of light is a high pressure mercury lamp having fixed electrodes.

- ii. Apparatus according to claim 1 in which the housing includes end-walls which close ends of the semi-cylindrical portion and the other portion of thehousing. f

5. Apparatusaccording to claim, 1 in which the housing includes end, walls which close ends of the semi-cylindrical portion and the other portion of the housing, said end walls having openings for insertion and removal of thelight source, and removable caps-closing said end openings.

6. Apparatusacco'rding to claim 1 and a presser cloth for applying a light-sensitive slfeet and original subject against the light transmissive semi-cylindrical surface. I

7. Apparatus according to claim 1 and 'a presser cloth for applying a light-sensitive sheet and original subject against the light transmissive semi-cylindrical surface, one end of said cloth being attached to the housing, the free end of said cloth having a transverse rod therein, hooks on said rod, and eyelets in said housing in which said hooks are adapted to engage to hold said cloth pressed on the semi-cylindrical surface.

8. Apparatus according to claim 1 and a presser cloth for applying a light-sensitive sheet and original subject against the light transmissive semi-cylindrical surface, a bar extending axially of the housing adjacent the lower edge of the semi-cylindrical portion, said bar being rotatably mounted, one end of said cloth being attached to said rod, a clip for clamping the cloth to said rod, whereby when said rod is rotated the cloth is wound thereon and tensioned, and means for securing said rod against unwinding.

9. Apparatus according to claim 1 and a presser cloth for applying a light-sensitive sheet and original subject against the light transmissive semi-cylindrical surface, and a plate hinged to said housing for supporting said cloth and work sheets in flat position, said plate being foldable against the housing when the apparatus is not in use.

10. Apparatus according to claim 1 and a presser cloth for applying a light-sensitive sheet and original subject against the light transmissive semi-cylindrical surface, said cloth being opaque over most of its area and having a small transparent area through which the light-sensitive sheet may be observed.

11. Apparatus according to claim 1, a screen rotatably mounted in said housing on the axis oi the half cylinder of material permeable to light rays the said screen screening the light transmissive copying portion when the work sheets are being applied and removed, and a handle for moving said screen.

12. Apparatus according to claim 1, a screen rotatably mounted in said housing on the axis of the half cylinder of material permeable to light rays the said screen screening the light transmissive copying portion when the work sheets are being applied and removed, and a handle for moving said screen, said screen having a reflective inner surface adapted to evenly reflect the light to the copying surface.

13. Apparatus according to claim 1, a screen rotatably mounted in said housing on the axis transmissive copying portion when the work sheets are being applied and removed, a handle for moving said screen, said screen having a reflective inner surface adapted to evenly reflect the light to the copying surface, and reflectors at the ends of the elongated light source for re-' fleeting light to the copying surface.

14. Apparatus for making prints on light sensitive sheets comprising a housing having a light permeable wall, a continuously operating mercury vapour lamp providing high intensity light in said housing, a screen, means for moving said screen between said lamp and light permeable wall and from between said lamp and wall at predetermined flxed time intervals, an electric circuit in which said lamp is connected, a multiple switch in said circuit, and a resistance having connections with said switch so that said resist ance can be connected in or out of the lamp circuit to alter the light intensity to allow operation of the machine with light sensitive sheets of diiferent sensitivity with equal time periods of exposure to the light.

15. Apparatus for making prints on light sensitive sheets comprising a housing having a light permeable wall, a mercury vapour lamp in said housing which operates with a supply of current above a certain potential as a high pressure lamp producing a high actinic ray radiation and below a certain potential as a low pressure lamp producing a low actinic ray radiation, circuits for supplying current from a source to said lamp, a multiple switch connected in said circuits for controlling the supply of current through said circuits, a resistance in one of the circuits connected with said switch, a screen, means for moving said screen to and from between said lamp and light permeable wall, whereby said lamp can be operated as a high pressure lamp with high actinic ray generation when using photo-sensitive sheets of low sensitivity when the current is supplied through the circuit not having the resistance therein and as a low pressure lamp of lowactinic ray generation when the current is supplied through the circuit having the reslst- 

